Spectral modulation detection and vowel and consonant identifications in cochlear implant listeners

Abstract

Speech understanding by cochlear implant listeners may be limited by their ability to perceive complex spectral envelopes. Here, spectral envelope perception was characterized by spectral modulation transfer functions in which modulation detection thresholds became poorer with increasing spectral modulation frequency (SMF). Thresholds at low SMFs, less likely to be influenced by spectral resolution, were correlated with vowel and consonant identifications [Litvak, L. M. et al. (2008). J. Acoust. Soc. Am. 122, 982-991] for the same listeners; while thresholds at higher SMFs, more likely to be affected by spectral resolution, were not. Results indicate that the perception of broadly spaced spectral features is important for speech perception.

Acoustic Temporal Modulation Detection in Normal-Hearing and Cochlear Implanted Listeners: Effects of Hearing Mechanism and Development

“…Basic psychoacoustic abilities have previously been shown to constrain hearing outcomes of CI users; for example, temporal modulation detection (Cazals et al 1994;Fu 2002;Won et al 2011;Gnansia et al 2014), spectral-ripple discrimination (Henry and Turner 2003;Henry et al 2005;Won et al 2007;Won et al 2010;Anderson et al 2011), spectral-ripple detection (Litvak et al 2007;Saoji et al 2009;Anderson et al 2012), Schroeder-phase discrimination (Drennan et al 2008), electrode discrimination (Henry et al 2000), and place-pitch discrimination (Donaldson and Nelson 2000). It should be noted that most of these previous studies have been conducted with postlingually deaf adults with CIs; thus, little is known about the development of psychoacoustic abilities in children with PLD who use CIs.…”

Relationship Between Behavioral and Physiological Spectral-Ripple Discrimination

“…Over the past few years, spectral-ripple discrimination has been widely used in a variety of behavioral experiments with normal-hearing (NH), hearingimpaired (HI), and cochlear-implant (CI) listeners (e.g., Supin et al 1994;Henry et al 2000Henry et al , 2005Won et al 2007;Litvak et al 2007;Saoji et al 2009;Won et al 2010). For example, the ability of subjects to discriminate a reversal in the phase of the rippled shape (Henry et al 2000(Henry et al , 2005Won et al 2007), and the ability to differentiate between a spectral-ripple stimulus and white noise (Litvak et al 2007) have been evaluated.…”

Assessing the role of spectral and intensity cues in spectral ripple detection and discrimination in cochlear-implant users

“…When spectral ripple detection thresholds are measured individually at different spectral modulation rates, the resulting pattern of thresholds as a function of modulation rate is referred to as the spectral modulation transfer function (SMTF) (Saoji and Eddins, 2007;Saoji et al, 2009). Eddins and Bero (2007) measured the SMTF in normal-hearing listeners for rates between 0.25 and 10 ripples per octave (rpo), and found that the general form of the SMTF in that range is bandpass, with best modulation detection in the region between 2 and 4 rpo, and poorer detection at lower and higher modulation frequencies.…”